Synthetic fiber dyeing with hexamethyl phosphoric acid triamide and chlorinated ethylene solution of disperse dye

ABSTRACT

A PROCESS FOR DYEING OR PRINTING TEXTILE MATERIAL MADE OF LINEAR POLYESTER, POLYAMIDE, CELLULOSE ACETATE OR ACRYLIC POLYMERS WHEREIN THE TEXTILE MATERIAL IS IMPREGNATED OR PRINTED WITH A SOLUTION OF A DISPERSE DYESTUFF IN A MIXTURE OF A CHLORINATED ETHYLENE AND UP TO 50% OF HEXAMETHYL PHOSPHORIC ACID TRIAMIDE, AND THE DYESTUFF IS FIXED ON THE FIBRE BY SUBJECTING THE MATERIAL TO A HEAT TREATMENT AT A TEMPERATURE BELOW THE SOFTENING POINT OF THE FIBROUS MATERIAL.

United States Patent US. Cl. 8-163 7 Claims ABSTRACT OF THE DISCLOSURE A process for dyeing or printing textile material made of linear polyester, polyamide, cellulose acetate or acrylic polymers wherein the textile material is impregnated or printed with a solution of a disperse dyestuif in a mixture of a chlorinated ethylene and up to 50% of hexamethyl phosphoric acid triamide, and the dyestuif is fixed on the fibre by subjecting the material to a heat treatment at a temperature below the softening point of the fibrous material.

It is known that fully synthetic fibres, especially polyester and nylon fibres, are difficult to dye with conventional aqueous dyestulf dispersions because of their compact hydrophobic nature. Polyester fibres must therefore be dyed either in the presence of so-called carriers or in costly pressure vats which may require a dyeing time of several hours. The possibility of dyeing linear polyester fibres is also considerably influenced by their degree of crystallinity. So-called textured fibres, in which the fibre structure has been subsequently changed by a physical treatment, for example to produce a crimp effect, have varying degrees of crystallinity and it is thus very difficult to obtain even dyeings.

A relatively frequent criticism in the case of polyamide materials is the striped aspect of the dyeings obtained. In most cases this is due to variation in the affinity of the polyamide fibre material which causes different dyestuif absorption. In many other cases it is a variation in the yarn quality, for example texturing faults or differences in tension produced by inaccuracies in stretching or in the yarn feed on reeling, knitting or weaving looms or irregularities in the polyamide structure which produce striped dyeings on yarn deformed in this manner. Striped dyeings, which are non-uniform over the width of the fabric, are also obtained on an increased scale when textile material made of polyamide filaments is dyed continuously. This uneven dyeing over the width makes it impossible to dye such textile material in the dyehouse in an acceptable quality by padding with an aqueous liquor and subsequent fixation in a continuous process.

The present invention is based on the observation that commercial textile material of hydrophobic fully synthetic fibres, filaments, as Well as yarns and knitted and woven fabrics made therefrom, especially those based on polyesters and nylon filaments, can be successfully dyed by replacing the usual aqueous liquor in which the dye 'ice stuif is dispersed by a solution of the dyestuff in an organic solvent mixture.

It has already been proposed to dye in high-boiling solvents, polyester fibres or filaments having an especially 7 low degree of crystallinity such as are obtained at an intermediate stage in the manufacture of polyester fibres, but it could not be foreseen that fully stretched commercial polyester fibres of a higher degree of crystallinity, ready for weaving, could also be dyed in a satisfactory manner in the presence of high-boiling organic solvents.

In fact, dimethylsulproxide has already been proposed as an organic solvent for dyeing hydrophobic fibres, but with this solvent the dyeings produced on polyester fabrics are not level. Furthermore, solvent mixtures have been proposed for dyeing polyester materials, but these solvents contain a flammable ingredient.

It is also known that hydrophobic fibres can be dyed with a mixture of a disperse dyestuff and a liquid or pasty dispersant which, if desired, may contain aliphatic alcohols, but these dispersants are not solvents in the usual sense.

One advantage of the use of organic solvents as dyeing media is that the dyed material is much more level, the dyeing all over the fabric being particularly more uniform.

Having regard to the more stringent regulations concerning the pollustion of water in force in many districts, the present process has the advantage that a smaller quantity of waste water is produced in the dyeing process.

Another advantage of the process of this invention compared with the conventional dyeing with aqueous dispersions of the dyestuffs is that it can be performed with the use of unconditioned dyestuffs, whereas in conventional dyeing processes from an aqueous dyebath it is always necessary to use specially conditioned dyestuff preparations to facilitate their dispersion in water.

Finally, according to the present invention dyestuffs can be used that have been found to be unsuitable for dyeing in conventional processes from an aqueous medium. Thus, the range of suitable dyestuflis is widened by dyeing from solvents.

The present invention provides a process for dyeing textile material made of hydrophobic polymers containing polar groups, ready for weaving, especially of linear polyesters and polyamides, wherein the textile material is impregnated or printed, preferably padded, with a solution of at least one dyestuff in a mixture of a hydrophobic solvent and up to 50% of a phosphorus compound containing oxygen, especially an alkylated phosphoric acid triamide, whereupon the dyestutf is fixed on the textile material fibre by subjecting the latter to a heat treatment, preferably a treatment with dry heat, at a temperature below the softening point of the fibrous material.

The present dyeing process can be applied to any type of hydrophobic fibre containing polar groups, for example cellulose 2 /2-acetate and triacetate fibres, acrylonitrile polymers and copolymers and especially polyester fibres and polyamide fibers. Polyolefine fibres free from polar groups are not included in fibres suitable for dyeing by the present process.

The preferred material to be dyed according to the present process is textile material made of aromatic polyesters, for example polyesters of terephthalic acid and ethylene glycol or 1,4-dimethylolcyclohexane, or copolymers of terephthalic or isophthalic acid and ethylene glycol.

The present dyeing process is also specially suitable for all synthetic polyamides, more especially poly-(hexamethylene-adipamide) or nylon 66, or poly-(e-caprolactam) or nylon 6, poly-(hexamethylene-sebacic acid amide) or nylon 610 and poly-( l l-aminoundecanoic acid) or nylon 11. The process of this invention yields especially good results in dyeing filament fabrics.

The hydrophobic solvents used in accordance with the invention must also be inert towards the fibres or filaments at the dyeing temperature; acetophenone or, if desired, halogenated hydrocarbons for example chlorobenzene and preferably aliphatic hydrocarbons for example, carbon tetrachloride, chloroform, methylene chlo ride, trichloroethylene, perchlorethylene, trichlorethane or dibromoethylene may be used.

Suitable phosphorus compounds containing oxygen are the dialkylphosphites for example dimethylphosphite or ethylphosphite, and the derivatives of phosphoric acid, G 5 )a 2 5 )3 (C6H5S)3PO 3 3)2 and more especially the hexaalkyl-phosphoric acid amides for example hexaethyl-phosphoric acid amide and preferably the hexamethyl-phosphoric acid triamide of the formula OP[N(CH In this context liquid tensides, that is to say liquids that contain a hydrophilic and a hydrophobic residue in one and the same molecule, are not covered by the term hydrophobic solvents, even when they are capable of dissolving the dyestuffs.

To prevent damage to the fibre a simple small-scale test may be made before proceeding with the dyeing to ascertain whether the fibre remains undissolved under the dyeing conditions in the presence of the solvent. If necessary, the time of contact between the solvent and the fibre may be shortened to prevent a major attack on the fibre, or a higher proportion of chlorinated hydrocarbons can be used.

The following structural classes of dyestuffs are suitable for use in the present dyeing process: monoazo and disazo dyestuffs, anthraquinone, naphthoperinone, quinophthalone, oxazine, phthalocyanine and methine dyestuffs, including the styryl, azamethine and azostryryl dyestuffs; metal complex compounds of the azo and formazan dyestuffs. Representatives of other suitable structural types may likewise be used.

From the tinctorial aspect, the following types of dyestuffs are specially suitable: water-soluble acid dyestuffs, including acid levelling dyestuffs which can be used for dyeing either in the presence of acetic or formic acid or in a neutral medium until the aqueous dyebath is exhausted; pre-metallized dyestuffs having a ratio of metal to dyestuff of 1:1 or 1:2, which may but need not contain groups imparting solubility in water; metal-free dyestuffs not containing groups imparting solubility in water (listed in the Colour Index as Solvent Dyes) which are soluble in ketones, esters, alcohols or aromatic solvents, and other organic dyestuffs free from groups imparting solubility in water, especially the so-called disperse dyestuffs defined in the Colour Index. Vat dyestuffs in the unreduced state insofar as they are soluble in one of the solvents mentioned above are more especially suitable for polyester fibres. The said dyestuffs are chosen according to their suitability for the individual type of fibre to be dyed. Polyester fibres are preferably dyed with disperse dyestuffs and polyamide fibres with water-soluble fibre-reactive dyestuffs or preferably with fibre-reactive disperse dyestufls.

The present process is preferably performed without addition of dispersants; this offers the advantage that the dyed textile material is easier to clean. But, if desired, non-ionic emulsifiers may be added to the dyebath or padding liquor, preferably in an amount not exceeding 40%.

Important members of such non-ionic emulsifiers belong especially to the following types of compounds:

(21) Ethers of polyhydroxy compounds, for example polyoxyalkylated fat alcohols, polyoxyalkylated polyols, polyoxyalkylated mercaptans and aliphatic amines, polyoxyalkylated alkyl-phenols and -naphthols, polyoxyalkylated alkylarylmercaptans and alkylarylamines;

(b) fatty acid esters of the ethylene glycols and polyethylene glycols as well as those of propylene glycol and butylene glycol, glycerol or polyglycerols and pentaerythritol, sugar alcohols for example sorbitol, sorbitans and saccharose;

(c) N hydroxyalkyl carbonamides, polyoxyalkylated carbonamides and sulphonamides.

Advantages emulsifiers in these groups are for example: adducts of 8 mols of ethylene oxide and 1 mol of para-tertiary octylphenol, 15 or 6 mols of ethylene oxide and caster oil, or 20 mols of ethylene oxide and the alcohol C H OH; adducts of ethylene oxide and di-(a-phenylethyl)phenols; polyethylene oxide-tertiary dodecyl thioether; polyamine-polyglycol ether or adducts of 15 or 30 mols of ethylene oxide and 1 mol of the amine C H NH or C H NH, or liquid polyethylene glycols.

The dyebath may further contain thickeners, for example cellulose esters or others, and also carriers.

It is advantageous to dye in the absence of dispersants. If necessary, any undissolved matter may be removed from the dyestuff solution by mechanical operations, for example filtration or centrifugation.

Padding (impregnating) is performed either at room temperature or with heating. After having been conveyed through the dyestuff solution the textile material is squeezed to the desired content of about 20 to 130% of impregnating solution referred to the weight of the dry fibre.

If desired, the impregnated or printed material leaving the padder or the printing machine is freed from the bulk of the adhering dyestuff solution by drying for a short time in a current of air heated, for example at 30 to C., or in another way, for example by centrifuging, or it is subjected to the fixing or thermofixation as it is. This is carried out at a temperature above C. preferably at a temperature of at least to 240 C. In any case the temperature during the fixing must not reach the softening temperature of the fibre.

The heat-setting is performed, for example, by steaming or preferably by a dry-heat treatment, for example by contact heat, treatment with a high frequency alternating current or infra-red irradiation.

The optimum conditions for the heat-setting treatment without damage to the fibre can be determined by means of a simple preliminary experiment.

Unless otherwise indicated, parts and percentages in the following examples are by weight.

EXAMPLE 1 A safety belt made of polyester is padded in the cold with a solution of 9 parts of the dyestuff of the formula described in Swiss Pat. 439,526

in 1000 parts of a mixture consisting of 931 parts of perchloroethylene, 36 parts of hexamethylphosphoric acid amide and 33 parts of ethylhydroxyethyl cellulose,

squeezed to an 85% uptake on the weight of the fibre, dried in a current of air heated at 40 to 50 C. and then ll heated for 90 seconds at 200 C.

A yellow dyeing fast to light and washing is obtained having a fastness to rubbing value of 4 to without any after-cleaning.

Instead of the dyestuff mentioned above the dyestuffs A NH(CH2)3N(CH3)2 given in Column I of the f011Wi 11g table y The resulting blue dyeing is fast to light and washing They Produce 011 Polyester material the Shades lndlcated and its fastness to rubbing is similar to that mentioned IIIH-CE? incolurrm II. 0 in Example 1.

ClHlCa I a Red N=N-C=N\ ClHtCs oQ 2 01 SN 0 02m 01 rangemcois -N=NN\ i C2H4Cl CH3 3 (|)H Yellow.

( JHa l on Compounds 1 and 2 above described in British Pat. EXAMPLE 4 and compound 3 m Brmsh A nylon filament fabric is padded in the cold with a EXAMPLE 2 solution of 6 parts of the dyestuif of the formula described in British Patent 848,236 Dyeing is carried out as described in Example 1 but with 9 parts of the dyestutf of the formula described in OH French Pat. 1,510,499 CFOHPCWMQWAQ 2H4- -om 10 f f CH3 2N I in 00 parts 0 a mixture consisting o 940 parts of perchloroethylene and 60 parts of hexamethylphosphoric 2 4 acid amide, squeezed to a weight increase of 50%, dried in a current of air heated at 40 to 50 C. and finally heat- The resulting red dyeing is fast to light and washing treated for 60 Seconds at and its fastness to rubbing is similar to that mentioned in The resulting Yellow dyeing is fast to light and Washing Example and contains a large proportion of chemically com- AM L 3 bined dyestutf.

Instead of the dyestuff mentioned above the dyestuffs Dyeing is carried out as described in Example 1 but listed in column I of the following table may be used.

with 9 parts of the dyestuff of the formula described in They produce on polyamide material the shades given in French Pat. 1,158,839 column II.

1 O OH Blue:

2 "1.2: H502 Red.

Br Br SN Yellowlsh CHzCHzOH red.

CHzCHzOH Compound 2 above described in Belgium Pat. 604,093 and compound 3 in British Pat. 895,424.

EXAMPLE 5 Dyeing is carried out as described in Example 4 but with 6 parts of the dyestuff of the formula described in British Pat. 901,434

021140 0 O CH2C1 The resulting red dyeing has properties similar to those mentioned in Example 4.

EXAMPLE 6 Dyeing is carried out as described in Example 4 but with 6 parts of the dyestuif of the formula described in British Pat. 895,424

The resulting blue dyeing has properties similar to those mentioned in Example 4.

EXAMPLE 7 parts of the dyestufl of the formula described in French Pat. 1,510,499

Cl i (fizHr- $-OH3 are dissolved in 100 parts of hexamethylphosphoric acid triamide and the whole is diluted with 885 parts of per chloroethylene. A farbric of polyacrylonitrile staple fibre is then padded at room temperature until it has absorbed 75% of its own weight of the liquor, dried in a current of air heated at 40 to 50 C. and heated for 60 seconds at 200 C. The fabric is then soaped at 60 C., rinsed in warm and finally in cold water and dried. A level red dyeing is obtained.

EXAMPLE 8 10 parts of the dyestuft of the formula described in French Pat. 1,158,839

h) NH-CHa are dissolved in 100 parts of hexamethylphosphoric acid triamide as described in Example 7 and diluted with per- 0 chloroethylene to 1000 parts. This liquor is used to dye a cellulose 2 /2-acetate fabric. The increase in Weight is about 50%. The fabric is intermediately dried and then heated for to seconds at 120 C. The after-treatment is carried out as in Example 7. A brilliant yellow dyeing is obtained.

EXAMPLE 9 in 1000 parts of a mixture consisting of 940 parts of perchloroethylene and 60 parts of hexamethylphosphoric acid triamide, squeezed to a weight increase of 60%, dried in a current of air heated at 40 to 50 C. and finally heattreated for 90 seconds at 200 C. The dyeing is aftertreated as described in Example 7, but it is soaped at 80 C. A strong yellow dyeing is obtained which is fast to light and washing.

We claim:

1. A process for dyeing linear polyester, polyamide, cellulose acetate or acrylic fibers comprising applying to said fibers a solution of a disperse dyestutf in a mixture of a chlorinated ethylene and up to 50% of hexamethyl phosphoric acid triamide, drying the fiber and then heating the fiber to at least C. and below the softening point of the fiber for a short period of time.

2. A process as claimed in claim 1 wherein textile material made of nylon.

3. A process according to claim 2, wherein a nylon fabric is used.

4. A process as claimed in claim 1, wherein the solvent is removed by evaporation.

5. A process as claimed in claim 1, wherein the textile material is rinsed in an aqueous medium after having been heat treated.

6. A process as claimed in claim 1, wherein nylon treated with a fiber reactive disperse dye-stuff.

7. A process according to claim 1 which comprises printiirijg linear polyester, polyamide, cellulose acetate or acrylic ers.

References Cited UNITED STATES PATENTS 3,082,052 3/1963 Goodings 8-100 FOREIGN PATENTS 913,646 12/ 1962 Great Britain 8--171 1,113,809 9/1961 Germany 8171 1,277,880 1/1961 France 8--171 1,092,880 5/ 1961 Germany 8-171 OTHER REFERENCES White: American Dyestuff Reporter, July 31, 1967, pp. 591-597.

DONALD LEVY, Primary Examiner US. Cl. X.R.

8-39, 41 B, 41 C, 41 D, 41 R, 41 A, 173 

